Testing of integrated circuits that contain a mix of RF circuits and logic circuits is described in an article by R. Nelson, titled “RF test join SOC ATE”, published in Test and Measurement world dated Apr. 1, 2002. Increasingly, state of the art semi-conductor integrated circuit manufacturing techniques make it possible to produce integrated circuits with integrated capability of handling RF signals. “RF”, as used herein, loosely refers to signals with frequencies used for wireless transmission, for example in microwave bands above 10 GHz, but also to lower frequency bands.
The main tests of RF circuits involves the application to the circuit of RF signals at frequencies that will be used during normal operation of the circuit, or measurement of such signals after their generation by the circuit. On the other hand, logic functions of integrated circuits are generally tested by applying logic test patterns and observing test responses at much lower frequencies. Test equipment for the latter type of test is generally standard in most integrated circuit manufacturing facilities and is applied to almost all more complex digital integrated circuits. On the other hand equipment for RF testing is not widely available and implies additional investment if integrated circuits with RF circuits have to be manufactured and tested.